Polyurea coating based on cyanoalkylated polyoxyalkylene polyamines

ABSTRACT

Polyureas prepared from an isocyanate and a cyanoalkylated polyoxyalkylene polyamine of the formula WHEREIN A is a cyano-lower-alkyl radical or hydrogen provided at least one A is a cyano-lower-alkyl radical are useful as spray coatings. These sprayed polyurea coatings are useful protective coatings which can be used in any field where protective coatings are desirable.

United States Patent [1 1 Rowton et al.

[ 1 Jan. 30, 1973 154] POLYUREA COATING BASED ON CYANOALKYLATEDPOLYOXYALKYLENE POLYAMINES [75] Inventors: Richard Lee Rowton; ErnestLeon Yeakey, both of Austin, Tex.

[73] Assignee: Jefferson Chemical Company, Inc.,

Houston, Tex.

[22] Filed: June 25,1971

[2]] Appl. No.: 156,925

Related US. Application Data [63] Continuation-impart of Ser. No.852,488, Aug. 22,

1969, abandoned.

52 us. Cl...., s.....201lZ-gn 2 9 77.5 AM 51 lm. Cl. ..C08g 22 02, C08g22/16 [58] Field of Search ....260/465.5 R, 584 B, 77.5 cu,

260/775 c, 75 NH, 77.5 AM, 2.5 AM

3,440,086 4/1969 Kerns ..1l7/105.5 3,236,895 2/1966 Lee et a1 3,654,3704/1970 Yeakey 3,666,788 5/1972 Rowton ..260/465.5

OTHER PUBLICATIONS Advance Technical Data .leffamine (TM)Polyoxypropyleneamines. Jefferson Chemical Co., Inc. Houston, Texas(1969) pages l-l0.

Primary ExaminerDonald E. Czaja Assistant Examiner-H. S. CockeramAttorney-John R. Kirk, Jr. et al.

[57] ABSTRACT Polyureas prepared from an isocyanate and a cyanoalkylatedpolyoxyalkylene polyamine of the formula R[(OCH2CH),,O ?H(l3H-NH-A]wherein A is a cyano-lower-alkyl radical or hydrogen provided at leastone A is a cyano-lower-alkyl radical are useful as spray coatings. Thesesprayed polyurea coatings are useful protective coatings which can beused in any field where protective coatings are desirable.

9 Claims, No Drawings POLYUREA COATING BASED ON CYANOALKYLATEDPOLYOXYALKYLENE POLYAMINES CROSS REFERENCE TO RELATED APPLICATION Thisapplication is a continuation-in-part of Ser. No. 852,488 filed Aug. 22,1969, now abandoned.

Richard L. Rowtons co-pending U.S. Pat. application Ser. No. 852,487,filed Aug. 22, 1969, now U.S. Pat. No. 3,666,788, discloses a method forthe synthesis of the cyanoalkylated polyoxyalkylene polyamines useful inthe practice of this invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The inventionpertains to the field of chemistry of protective coatings of polyureas.

2. Description of the Prior Art It is known that aromatic diamines areused as curing agents for polyurea-polyurethanes. For example, SpencerKellogg Technical Service Bulletin TS 6893 (Copyright Spencer Kellogg,Division of Textron, lnc., 1968) suggests a coating composition whichcontains a chlorinated aromatic diamine. Polyoxyalkylene diamines areknown to be such rapid curing agents for polyurethanes that they areuseless in polyurethane sprays. In the Upjohn Company Technical BulletinTB-402, p. 9 Aug. 15, 1966), it is reported Polyoxypropylene diaminescause a rapid viscosity build-up when used in these formulations indiscussing curing agents for spray coatings of polyurethanes.

In spray polyurea and polyurea-polyurethane coatings, a short delay incuring time is necessary. Aliphatic amines in general andpolyoxyalkylene polyamines in particular react almost instantaneouslywith isocyanates; therefore, these amines cannot be used in spraycoatings of polyureas utilizing an isocyanate or isocyanate-prepolymerbecause of the immediate gel or hardening of the polyurea when the amineis added. By using the cyanoalkylated polyoxyalkylene polyamines of ourinvention, gel times aresuch that good mixing of the isocyanate andamine can be obtained and the sprayed material has time enough to adhereand level before gelation of the polyurea coating occurs.

SUMMARY OF THE INVENTION Our invention is polyurea protective coatingsprepared by reacting cyanoalkylated polyoxyalkylene polyamines withisocyanates or isocyanate-terminated urethane prepolymers. The inventionis particularly applicable to sprayed polyurea coatings. Thecyanoalkylated polyoxyalkylene polyamines used in our invention arecompounds of the formula CH: CH: HzNOHCHKOCHilHhNHz or mixtures thereofwhere R is the nucleus of an oxyalkylation-susceptible aliphaticpolyhydric alcohol containing 2-12 carbon atoms and 2-8 hydroxyl groups,A is hydrogen, or a cyano-lower alkyl radical having one or two carbonatoms between the nitrogen and cyano radical provided at least one A isa cyano-lower-alkyl radical, Z is an alkyl group containing l-18 carbonatoms, X and Y are hydrogen or Z, n has an average value of 0-50 and mis 2-8. The methyl and ethyl alkyl groups of A may be substituted withlower alkyl groups. Oxyalkylation-susceptible alcohols are alcoholswhich are added to alkoxides.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The cyanoalkylatedpolyoxyalkylene polyamines useful in our invention are prepared frompolyoxyalkylene polyamines which are disclosed in Lees US. Pat. No.3,236,895 (1966) and Yeakeys co-pending US. Pat. application Ser. No.67,970 filed Aug. 28, 1970, now US. Pat. No. 3,654,370. Polyoxypropylenediamines having a molecular weight of about to about 2,000 are useful inpreparing the cyanoalkylated polyoxypropylene diamines of our inventionand polyoxypropylene diamines having a molecular weight of about 190 toabout 1,000 are preferred starting materials for the compounds useful inour invention. These polyoxyalkylene diamines have the general formulaRKQCHQOH).,ooH-6i1 -NH A I Y where y is a number from about 2 to about16. Polyoxypropylene triamines of the formula on, I CH2(OCHz--(l1H-);NH2

CH: cmoHT-c CH1(0-CHzJJH-), NH2

where x y z is an average of 5.3 are also useful starting materials forthe compounds of our invention.

N-Cyanoalkylated polyoxypropylene diamines and triamines are liquids,thin enough to be sprayed without dilution. Aromatic amines aregenerally solids which must be dissolved in solvents in order to beuseful. Aromatic amines may be conveniently utilized in conjunction withthe cyanoalkylated amines of our invention by dissolution in the latter.

The polyurea molecule may contain in addition to urea groups, urethanelinkages, ether linkages, ester linkages, etc.

With this invention it is not only possible to use aliphatic isocyanatesas reactants, but also the more commonly used aromatic isocyanates,which are much more active than aliphatics. Not only canisocyanateterminated urethane prepolymers be used (e.g. products madefrom polyether polyols or polyester polyols and excess isocyanates, suchas toluene diisocyanate), but also the isocyanates can in many cases beused alone.

The great variation possible in the amine component of the sprayformulation makes possible the use of a wide range of isocyanates. It ispossible to use an isocyanate component containing little or no solvent.

Examples I and II, and Ill, infra, illustrate typical preparations ofthe compounds useful in our invention.

EXAMPLE 1 Amine Meg./g. Primary 0.19 Secondary 6.69 Tertiary 0.02

Total 6.90

Thus, the N,N'-disubstituted product of the formula CH3 3E3NCCHzCHQNHCHCHrO-CHz-CH-O-CHr H-NHCHsCHzCN was produced in 97 percentyield. The remaining cyanoethylated compounds useful in our inventionare prepared in the same manner, and comparable results are obtained inpolyurea coatings using polyoxyalkylene polyamines cyanoethylated withacrylonitrile or methacrylonitrile.

EXAMPLE II To 400 g. (1 mol) of nitrogen-blanketed polyoxypropylenediamine of 400 molecular weight was added dropwise with stirring 163 g.2 mols) of 70 percent aqueous glycolonitrile. The mixture exothermed,and the reaction was allowed to proceed at 40 50C. After the nitrileaddition was complete, the reaction mixture was allowed to stand forseveral hours at ambient temperatures. A 100 percent excess of calciumhydroxide was added to neutralize the 0.5 percent phosphoric acidpresent in the nitrile. After standing a few more hours, water wasstripped out at up to 120C. under full vacuum. Filter aid was added andthe mixture filtered. A light brown liquid was obtained. The remainingcyanomethylated compounds useful in our invention are prepared in thesame manner and comparable results are obtained using polyoxyalkylenepolyamines reacted with glycolonitrile or lactonitrile. The reactionspreparing the'compounds useful in our invention are selective in thatN,N'-disubstitution takes place. If complete substitution of the aminehydrogens occurred, the products would not be satisfactory for use ascuring agents for polyureas.

EXAMPLE "I I A partially cyanoalkylated polyoxypropylene triamine wasprepared according to the following procedure which includes thesynthesis of the polyoxypropylene triamine.

The polyoxyalkylene triamine was prepared in a 7- gallon high pressurecontinuous reactor over a nickelcopper-ch'romium catalyst at 203C and2,500 psig. The feed rates were 74 lb/hr ammonia, 27 lb/hr propyleneoxide adduct of trimethylolpropane of 400 molecular weight and standardcubic feet per hour dissociated ammonia. The product was recovered byammonia stripping the reactor effluent to 60C and then vacuum strippingto remove water at 25 mm Hg, absolute pressure, to a final temperatureof C. The product analysis was as follows:

s-ls Total Acetylatables 6.95 Total Amine 6.60 Primary Amine 6.26

The product was a 440 molecular weight polyoxypropylene triamine.

The partially cyanoethylated polyoxypropylene triamine was prepared byheating a mixture of 804 g. (1.81 mols) polyoxypropylene triamine(synthesis described in preceding paragraph), 212 g. of acrylonitrile (4mols) and 40 g. of water at 75C for 2 hours. Water and other lights werestripped at up to l 10C. and down to 2 mm Hg. The product had thefollowing analysis:

Amine Meg/g. Primary 1 l6 Secondary 4. l0 Tertiary 0. 10

The following tables illustrate our invention in more detail. Gel timesare reported in seconds. The following abbreviations are used in thetables:

Amines JEFFAMINE D-x Polyoxypropylene Diamine of The abbreviations forthe component formulations of the polyureas are illustratedvas follows:3:1 LMDIzT- Dl/PPG-800 (2/1) is a mixture of three isocyanateequivalents of LMDI and one equivalent of a TDl/PPG800'prepolymer, thelatter being made from two equivalents of TDI and one equivalent ofPPG-800. Pigments and other modifiers may be included in the formulationof polyureas. In each of the Tables, a theoretical equivalent amount ofthe amine component was added to the isocyanate component contained in asmall cup while the mixture was stirred as rapidly as possible with apaddle-type stirrer. After i seconds of Reflctgnts Solvent m m 3;!stirring, a portion of the mixture was poured onto a pan 'mgg Name a andspread out with a spatula to form a film. Gel time in the cup was notedand recorded, and the physical na- TD] JEFFAMINE methy ethyl 65 ture ofthe film was recorded. The gel times for the for- 5 mediate mulationsillustrate the utility of the polureas as LMD! TQQ gg s l sprayedcoatings. The practical gel times shown in the y y mediate tables,infra, make it possible to use the polyureas for D-.400 ketone sprayedcoatings. If a solvent was used, it was dis- PM JEFFAMINE methyl 65 htributed between the two components so that each 0-400 ketone componentwas of low viscosity. Films containing sol- EE ggg iz y 50 vent weredried in an oven at 80C. before evaluation. JEFFAMINE ethoxy ethyl 50Those mixtures marked with an asterisk did not gel, mediate butthickened to a fairly stiff consistency in the time LMDI/ T403 camenoted. Effective amounts of cyanoalkylated polyoxyal- PPG- JEFFAMINEmethyl ethyl 65 imkylene polyamines include a percent range above or 600(6") D400 kemne below the theoretical equivalent amount of aminecomponent to isocyanate component. A stoichiometric Example IVillustrates a polyurea spray coating using balance of reactants ispreferred. JEFFAMINE is a rethe cyanoethylated 400 molecular weightpolyoxgistered trademark of Jefferson Chemical Co., lnc., ypropylenediamine of our invention. Houston, Texas. I

IV The data in Table I illustrate the practical gel times EXAMPLE ofpolyureas obtained from cyanoethylated polyox- Component Aa 50:50 weightpercent blend of ypropylene diamines and triamines reacted withisoliquid diphenylmethane diisocyanate and hydrogenated cyanates. liquiddiphenylmethane diisocyanate containing 7.3

- 'ii liaLE i Reactants Solvent Gel Amount, time, Isoeyanate componentsAmine components Name percent see. Nature of film BCE/Jefiarnine D400.Methyl ethyl ketone.. 50 15 Soft and pliable. CE/Jeffamine D-400. d 6517 Stiff and strong.

BClg/Jeffamine D-400 o CE/Jefiamine D-4 BCE/Jefiamine D400.

..--d0 65 26 Fairly stiff and strong.

. 60 Soft and fairly strong.

..- 30 Slightly stiff. Fairly resilient. 50 16 Soft. Strong and elastic.

I.- LMDI/PPG-SOO (2/1) Toluene LMDI/PPG-SOO (6/1) CE/Jefiamine D-4OOMethyl eth 65 18 Fai 11" ly stifi. Fair strength and '8- -s1 ience.

PAI/PPG-fiOO (15/1) BCE/Jefiamine D400 do 65 12 Soft and pliable.

1:2 HMDIzLMDI/PPG-800 (6/1)- CE/Jetfamine D-400 do 4 Slightly stiff.Good strength and e astieity.

1:1 HMDIzLMDl/PP G-lOOO (4/1) do None 15 Soft and elastic.

1:2 PAI:TDI/PPG600 (2/1) BCE/Jeffamine D-230. Methylene chloride.... 3515 Soft and pliable.

1:1 LMDIzLMDI/PPG-SOO (2/1). do Toluene 12 Faiil-ly stifi. Fair strengthand re- Sl ience.

111:2 HMDIzPAI :TDI/PPGO (2/l). CE/Jefiamine D-230 Methylenechloride.... 35 8 D0.

LMD I/PP G-SOO (2/1) TCE/Jeifamine I403..... Methyl ethyl ketone. 7 Softand elastic.

HMDI/PPG-8OO (2, 1) CE/Jeffamine I403 Toluene 60 D0.

2:1 HMDIzTDI/PIG-IOOO (2/1) BCE/Jeffamine T-403.. None 15 Faiiiilystiff. Fair strength and res ienee.

a 5-6 minutes.

The data in Table II illustrate the practical gel times meq. isocyanateper gram-and component Bthe obtained with cyanomethylatedpolyoxypropylene monocyanoethylated 400 molecular weight polyoxdiaminesand triamines. ypropylene diamine containing 4.4 meq./g. of aminoReactants Solvent Gel Amount time, isocyanate components Aminecomponents Name percent see. Nature of film TDI BCllrllJeffamine D400...None 30 Soft and elastic. LMDL. BCM/Jefl'amine D-40O do *10 Fairlystiff. Fair strength and reslllence- LMD CM/Jeilemine D400. Methyl ethylketone.-. 65 Stifi and strong. PAL. do do 65 D0. PAL. llCM/Jefl'aminel)-400... Methyleneehloride.... 35 20 Soft and pliable. HMI)!(Jill/Jeil'mnine 400 None *60 Somewhat stifi. Fair resilience. 821 11M!l/ll(i8 BUM/Jeil'nmine D400 do 15 Soft and pliable. 1:2 lAlzTDl/llU-GOO(2/1) CM/Jeifnmine l)230 Meth ene chloride. 35 45 Soft but strong.

'- 3-30 minutes. 1% minutes.

The data in Table lllillustrates the impracticality of hydrogen anddiluted with 5 percent of its weight of using polyoxyalkylene polyamineswith isocyanates for methylene chloride-were pumped through atwopolyurea coatings because of the extremely short gel componentairless Gusmer spray rig at a component times. 5 B/component A ratio of1.67/1. In the spray rig, the

two accurately metered streams of reactants were TABLE III 7 broughttogether in a small chamber, rapidly mixed,

and ejected through a spray nozzle. The spray was applied to a rigidurethane foam substrate, whereon it gelled within a few seconds. Thesprayed film thus protects the foam from abrasion and degradation. Usingthis technique, a sprayed film of any thickness can be applied to asurface. These sprayed polyurea coatings are useful protective coatingswhich can be used in any field where protective coatings are desirable.

We claim:

1. A polyurea composition obtained by reacting with an organicpolyisocyanate or isocyanate-terminated prepolymer a cyanoalkylatedpolyoxyalkylene polyamine ofthe formula or mixtures thereof wherein R isthe nucleus of an oxyalkylation-susceptible aliphatic polyhydric alcoholcontaining 2-12 carbon atoms and 2-8 hydroxyl groups, A is acyano-lower-alkyl radical or hydrogen provided at least one A is acyano-lower-alkyl radical, Z is an alkyl group containing 1-18 carbonatoms, X and Y are hydrogen or Z, n has an average value of -50 and m is2-8. g

2. A composition according to claim 1 wherein the cyano-lower-alkylradical is cyanoethyl. 3. A composition according to claim 2 whereincyanoalkylated .polyoxypropylene diamine is a compound of the formulawherein y is a number from about 2 to about 16.

4. A composition according to claim 3 wherein the cyanoalkylatedpolyoxypropylene diamine is a compound of the formula CH3 CH3NCOHzCH-QNHJH-CHz-O-CHz-(bH-O-CHr- CH3 (SHNHCHzCHzCN 5. A compositionaccording to claim 2 wherein the cyanoalkylated polyoxypropylenetriamine is-a compound of the formula wherein x y z is an average of5.3.

6. A composition according to claim 1 wherein the cyano-lower-alkylradical is cyanomethyl.

7. A composition according to claim 6 wherein the cyanoalkylatedpolyoxypropylene diamine is a compound of the formula wherein y is anumber from about 2 toabout l6.

8.v A composition according to claim 7 wherein the cyanoalkylatedpolyoxypropylene diamine is a compound of the formula 9. A compositionaccording to claim 6 wherein the cyanoalkylated polyoxypropylenetriamine is a compound of the formula wherein x y z is an average of5.3.

k III

1. A polyurea composition obtained by reacting with an organicpolyisocyanate or isocyanate-terminated prepolymer a cyanoalkylatedpolyoxyalkylene polyamine of the formula or mixtures thereof wherein Ris the nucleus of an oxyalkylation-susceptible aliphatic polyhydricalcohol containing 2-12 carbon atoms and 2-8 hydroxyl groups, A is acyano-lower-alkyl radical or hydrogen provided at least one A is acyano-lower-alkyl radical, Z is an alkyl group containing 1-18 carbonatoms, X and Y are hydrogen or Z, n has an average value of 0-50 and mis 2-8.
 2. A composition according to claim 1 wherein thecyano-lower-alkyl radical is cyanoethyl.
 3. A composition according toclaim 2 wherein cyanoalkylated polyoxypropylene diamine is a compound ofthe formula wherein y is a number from about 2 to about
 16. 4. Acomposition according to claim 3 wherein the cyanoalkylatedpolyoxypropylene diamine is a compound of the formula
 5. A compositionaccording to claim 2 wherein the cyanoalkylated polyoxypropylenetriamine is a compound of the formula
 6. A composition according toclaim 1 wherein the cyano-lower-alkyl radical is cyanomethyl.
 7. Acomposition according to claim 6 wherein the cyanoalkylatedpolyoxypropylene diamine is a compound of the formula wherein y is anumber from about 2 to about
 16. 8. A composition according to claim 7wherein the cyanoalkylated polyoxypropylene diamine is a compound of theformula